PORTLAND, Ore. — Oak Ridge National Laboratory researchers are citing evidence that high-temperature superconductivity derives from the same mechanisms regardless of materials. That finding has prompted speculation that magnetic spin excitations that couple electrons is the key ingredient for superconductivity.
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Spin excitations in a superconducting material's performed at Oak Ridge National Laboratory support the theory that magnetic properties cause high-temperature superconductivity. |
Magnetic interactions "provide the glue that binds the electrons together," Oak Ridge lead researcher Mark Lumsden. "The pairing up of electrons is essential for the formation of the macroscopic quantum state giving rise to superconductivity."
High-temperature superconductivity could result in ultra-fast electronic devices that capitalize on high-speed electrons traveling in a material whose resistance has been reduced to zero. Levitating trains, ultra-sensitive sensors called superconducting quantum interference devices and nuclear magnetic resonance imaging use superconductors.
Superconductor devices must be super-cooled, which relegates their use to high-end applications. If room-temperature superconductors could be perfected, then electronic devices could operate faster through electron transport without resistance.
Last year, Japanese researchers discovered a new type of high-temperature superconducting material based on iron. Other high-temperature superconductors were based on copper. Research ensued on whether magnetic properties were also the suspected key to iron superconductors, or whether a new mechanism was discovered.
Now, Oak Ridge researchers claim that if magnetism explains copper high-temperature superconductors, then it will also explain iron-based superconductors.
Using the Spallation Neutron Source and the High Flux Isotope Reactor, the researchers applied intense neutron beams to image single crystals of superconducting iron, tellurium and selenium materials. They also observed the same spin excitations that are believed to be the source of superconducting in copper based materials called cuprates.
